Moero! Pegasus Ryuseiken - S1-E2
Other mistake: In the ending shot of the tournament bracket showing the potential future opponents, the two saints' names are written the wrong way, as "DORAGON" and "ANDOROMEDA", instead of Dragon and Andromeda. (00:22:00)
Plot hole: When Chutora and Kurotora, imprisoned in a mountain temple, see Sniper, they immediately recognise him, even though they have never seen him in the series.